第三部分 状语从句
一、知识点拨
（一）时间状语从句 (Adverbial Clau of Time)
问题一：引导时间状语从句的连接词哪些？
引导时间状语从句的常用连接词有：while, when. whenever, before, after, since, till, untill, once, as, as soon as, no sooner ... than, hardly / scarcely / barely ... when, the moment, the minute, the cond, the instant, every time, each time, next time, the first time, the last time, by the time, directly, immediately, instantly等。
问题二：when, while和as的用法有何区別？
1．when既能表示时间点，也能表示时间段；while只能表示时间段，如：
① When/While our English teacher was explaining the grammar to us, the headmaster came in and stopped him.
② Our English teacher was explaining the grammar to us when the headmaster came in and stopped him.
2．while引导的从句中的动词通常为延续性动词，且常可用进行时。如：
While her classmates were looking for jobs, she was busy writing her graduating thesis.
3．若从句动作发生在主句动作之前，通常用when引导从句。如：
When she comes, I shall tell her to wait for you.
4．as强调伴随，常指两个动作同时发生。如：
As she entered, she responded pleasantly to the interviewer's greeting.
5．若从句表云“随着 ... （时间）的流逝”，只能用as。如：
As the day went on, the weather got wor.
6．while还可作“而”解，表示对比。如：
Some people waste food while刻舟求剑的近义词 others haven't enough.
7．当主句是过去进行时、过去完成时，或was/were about to do o sth等结构时，从句用when引导，且只能置于主句后面。从句中谓语动词通常是瞬间动词的一般过去时。这时when作“这时／正在那时，（突然） ...”解。如：
① He was walking along the street when he ran into an old friend.
他正在街上走，突然遇封一位老朋友。
② I had read only a few lines when I heard the bell ringing.
我只读了几行字，这时我听到铃声响了。
③ He was about to return to the path when he saw a river nearby, so he went to have a clor look. 他正要回到小路上，这时他看见附近一条河，于是他走近看个仔细。
④ I was halfway back to the cottage where my mother lived when Susan caught up with me.
我正在回母亲村子的半路上，这时Susan赶了上来。
问题三：after和before的用法须注意什么？
1．after从句的动作发生在主句动作之前，故若主句的动词是过去时，从句通常用过去完成时，也可用过去时；而before从句的动作发生在主句动作之后，故若从句的动词是过去时，主句通常用过去完成时，也可用过去时。如：
① He bought a hou after he sold/had sold his car.
② 儿童饮食Before she went to the interview, she made / had made two journeys.
2．before在运用中还须注意：
（1）before与can连用时，可解释为“还来不及…”。如：Before I could explain, the cashier barked, "Can't you e there's a queue? Go to the end and wait your turn."
（2）before从句在主句后面时，可解释为“就；才”。“It is + 时间段 + before ...”的句型。解释为“... 时间之后，... 才 ...”。否定句“It is not long before ...”解释为“不久， ...”。另外，
谢霆锋的歌
注意，"before long"表示“不久／一会儿之后”，如：
① He hesitated long before he cho a proper answer.
② It was a long time before I got to sleep again.
③ It won't be long before you are of age.
④ It looks as though it will snow before long.
佳句大全（3）before有时可解释为“然后”。如：
Plea think it over before you decide to do anything.
问题四：since的用法须注意什么？
i. 通常，since从句中谓语动词用一般过去时，主句的谓语动词用现在完成时。但主句若表示“已经有 ... 时间了”，则多用一般时，即“|It is + 时间段 + since ...”句型，解释为“自从…以来，已经有 ... 时间了”。如：
① Since the World Cup began, all of the winning teams have been from Europe or South America.
② It is many weeks (=It has been many weeks) since提单样本 we last met.
ii. 如果since从句的谓语动词是延续性动词，若从句用一般过去时，则表示所指状态结束以来；若从句用现在完成时，则表示所指状态开始以来。如：
He has visited me frequently since I was ill. 自从我病愈以来，他经常来看我。
He has visited me frequently since I have been ill. 自从我病倒以来；他经常来看我。
She has lived in Paris since she was married. 她离婚以来一直住在巴黎。
She has lived in Paris since she has been married. 她结婚以来一直传在巴黎。
问题五：till和until的用法须注意什么？
till和until在引导时间状语从句时通常可以互换。需注意的是：
1．用于肯定句时，表示“做某事一直做到某时（为止）”，主句中通常用延续性动词；用于否定句时，表示“直到某时才（开始）做某事”，主句动词可以是延续性动词，也可以是瞬间动词。换句话说，若主句动词是瞬间动词，则只能用于否定句中。如：
① Amy's next step was to arch the newspaper until she found a suitable vacancy and write a letter of application.
妥当② Until I read about the writer I knew little about his novels.
2．从句中用一般时或完成时，主句却用一般时或将来时。如：
① They will fight until they overthrow / have overthrown the other.
② I watched him until he disappeared / had disappeared from sight in the distance.
3．从句在句首时多用until。如：
Until he returns, nothing can be done. 他不回来什么也做不成。
4．与when连用提问时，until置句首。如：
---- Until when are you staying?
---- Until next Friday.
5．Not until位于句首时，主句的主谓结构须用（部分）倒装语序，如：
孙组词语Not until the war ended did they meet again.
6．"... not ... until ..."的强调结构是“It is not until ... that ...”，注意强调句中勿倒装。如：
It was not until the game had begun that he arrived.
问题六：表示“一…就…”的结构有哪些？
1．as soon as从句表示“一 ... （就 ...”。从句中用一般现在时或一般过去时，也可用现在完成时或过去完成时。如：
南满洲As soon as the poor mother heard/had heard the news that her son was kidnapped, she fainted.
2.．"no sooner ... than ..."和"hardly / scarcely / bare1y ... when ..."，表示“一 ... 就 ...”。须注意的是：
